Get rid of quizBackground since it's not being used

I think at one point this has some sort of paper texture for a
background but it doesn't anymore
Get rid of answer holder class

It was only being used to set the height of the area where the answers
show up and that's keeping us from getting responsive
Get rid of correctAnswer class

We can do the same thing with some p tags and strongs
Get rid of a lot of unused classes and unnecessary styles

haven't checked in IE